Wheel of road vehicles



May 2, 1933. N. STRAUSSLER WHEEL OF ROAD VEHICLES Filed Nov. 10, 1928 2Sheets-Sheet l w/iw M W W y 1933. N. STRAUSSLER 1,906,776

' WHEEL OF ROAD VEHICLES Filed Nov. 10, 1928 2 Sheets-Sheet 2 PatentedMay 2, 1933 UNITED PATENT. orrlca 5 CORPORATION, A coaronarronornnrawann WHEEL or ROAD vEHIcLEs f hpplic'ation flled November 10,1928, Serial No. 318,480, and in Great Britain November, 1987.

' This invention relates to wheels of road vehicles of the kind in whichteeth or spikes,

technically called grousers. are caused to tiwhen traveling on softground in order to obtain a driving grip on: the ground, but whentraveling'on a hard surface the said teeth retire within the peripheryof ;-the wheel. In cases where such protusion has been effected andretraction permitted by springs acting in a radial direction relative-V1y to the wheel, the said springs continually pass from an operativeposition to aninoperative position, and viceiversa, so :that theyquickly wear out.

" 1 One of the objects of this invention is to produce in wheels havinga number of spring-impelled teeth the same conditions in h the springsas thosewhich occur in the case when 'a loaded condition has beenestablished, play of, the springs is notrequired 1 so long asthe-vehicle is smooth" road.

Another object is-to provide a vehicle wheel having'a luralit'y ofspring-impelled, protruding teet or grousers, with which traveling on apenetration may be achieved, on fairly hard ground, and'in which, atalltimes, the

ground and the torque upon the wheel.

According to the invention a numberof teeth, spikes, or grousers aremovably mounted orpivoted on a part of the wheel, and also on a ring ordisc which is capable of rotary movement relativelyto the wheel, andmeans are provided for moving the said 49 ring or disc insuch adirection that by the consequent movements of said members or levers allthe teeth are protruded beyond the periphery of the wheel, or retracted,according to the direction of the lsaidmovement;

each grouser into the ground is governed ofthe leafsprings of vehicles,that isto say,

inafter mentioned.

amount of penetration is automatically ad- 'grouser shown in'Figure 6.

justed dependent upon the condition of the I rubber or other suitablematerial whichnor- 1 members or leverseach carrying oneor more Thepenetration ofby the relative locations of the pivot point I on'thewheel and the tip of the grouser, as will be explained in more detail inconnec tion with the drawings. a e i In order that the said inventionmaybe clearly understood and readily carried into effect, the same willnow be described more fully with reference to the accompanying drawings,in which Figure 1 represents in elevation the inner I side of a wheelembodying this invention. fFigure 2 is a central vertical sectionlthere-0 I e. b

Figure 3 is an, elevation of the outerside ofthe wheel.

Figured is a plan of the control mechanism seen in Figure 2.. h Q I onof the Figure 5 is a transverse secti locking-device seen in Figure 3. pFigure 6 illustrates a m0dificati0n" here-' Figure 7 is a force diagramshowing the various forces which are exerted upon a grouser upon initialcontact with the ground. Figure 8 is is a force diagram 7 similar toFigure 7, but representing the forces'acting afterinitial penetration ofthe ground by the grouser.

F igure' 9 is an end View of the modified r so A indicates the wheelhavingla tire (I, of v mally runs on the ground, B the control disc, andC, O the grousers, which are curved teeth, and each of which is formedinte- 35 V grally with a lever D. This lever D has two arms, namely 'ashort arm d boredto rock freely on a pivot'bolt; a, secured toa ring orflange extension a on the wheel, and a long arm d which in this exampleis slotted to 9 e embrace a pin 12' secured in the control discB,although it will be understood that any suitable equivalent structuremay be sub stituted for the pinand slot connection here-- in shown. PinsE are secured at one end to the control disc B and extend freelythroughslots 0L in the wheel A (Figure 3), having secured 'attheir outer endsbracket like members 6 which serve'not only to con 'nect'one end offeachofa plurality of coiled springs F to pins E but also to hold disc B incooperative relation with wheel A. Fur thermore, as is clear from Figure2, arms (1 of the grousers, the latter being secured to rim a of wheelA, also serve to maintain control disc B in its proper position. Theother ends of coiled springs F are secured to lugs a bolted to thewheel, these springs tending to cause an angular movement of the pins Eand the disc B in the direction of the arrow seen in Figure 3 to theextent permitted by the slots at. Outward movement of grousers C is notonly limited by the co operative action of pins E and slots a but alsoby the provision of positive stops a secured to flange a of the wheel,and against which a flat side 0Z of lever D is adapted to abut. Thisangular movement of the disc B relatively to the wheel A causes all thegrousers C to be projected into the posi tions seen in Figure 2 and infull lines in Figure 1, but a reverse movement of the disc, (that is, ina counter-clockwise direction, viewing Figure 1) will cause all thelevers D tobe thrown into the position in which one of the said leversis indicated in dot-anddash lines in Figure 1, the grousers beingtherefore Withdrawn within the periphery of the wheel. It is immaterialwhether the disc B is arranged to overrun the wheel or to lag behind itto effect the automatic protrusion of the grousers. When travelling on ahard surface, such as that of a good road, the action of the springs Ftending to cause protrusion of the grousers is resisted by the roadsurface, so that the points of all the grousers are kept just level withthe tread of the wheel. On reaching softer ground, however, the pointsof the teeth are caused to enter it by the combined action of the saidsprings F, F, and other forces later to be described, to an extentdependent on the degree of softness of the ground and the torque uponthe wheel, and within their outward limit of movement, thus not onlyincreasing the are of contact with the ground but also using the groundas a rack on which they can roll, the curved shape of the teethfacilitating their withdrawal as they are carried round withoutunnecessary digging or rut-forming in the ground.

As shown in Figure 1, when the grousers are in their normal, protrudingposition, the toothed portions G are substantially radially disposedwith respect to the wheel A, and peripherally ofiset from bolts (:9,their pivot points. With this construction, any pivotal movement of thegrousers about bolts a causes an up-and-down, or substantially radialmovement of the grouser teeth, thus providing maximum penetrationcausation with a minimum fore-and-aft movement. This arrangement is alsoconducive to maximum torque efliciency, since after initial penetrationby the grousers has been efl'ected, the torque upon the wheel is exertedthrough pivot bolts (4 upon the grousers in a direction tangential towheel A, and hence substantially perpendicular to the direction ofpivotal movement of the grouser teeth, and therefore works against theresistance of the ground, giving the wheel a positive motion -forward,and is not expended in swinging the grousers about their pivots.

It is desirable to provide means whereby the driver can eithermomentarily prevent the protrusion of the grousers, or look them in theretracted position so that the vehicle can travel for a long distancewhile they remain inoperative, and such means are more particularlyillustrated in Figures t and 5. A lever G pivoted on the wheel axle H ath is adapted to be operated through suitable connections (not shown)from a handle under the control of the driver. This lever is operativelyconnected with a ring or socket J by means of arms: 9 having pins gwhich engage corresponding recesses i in socket J, and a movement of thesaid lever in the direction of the arrow 9 causes the socket to move inthe direction of the arrows j to engage a series of rollers K mounted injaws m on the ends of levers lVI secured to one end of and pivotallymounted by stub shafts m journalled in suitable bearingbosses a carriedby wheel A secured to the other end of shafts m are levers m havingspherical ends m which work in slots N in the control disc. This axialoutward movement of socket J and its engagement with rollers K rotatelevers M in a counter-clockwise direction, as viewed in Figure 4, ontheir stub shafts m thereby causing a corresponding movement oflevers122.".- Due to the engagement of spherical ends m and slots N in controldisc B, this latter movement of levers m in turn causes acounter-clockwise movement, as viewed in Figure 1, of disc B therebydrawing in all the grousers. When the driver releases the said handle,the springs F tend to protrude the grousers again. If, after operatingthe lever G, when the lug P (Figures 1, 3 and 5) on the disc B haspassed the slot R in the wheel A, the driver pushes the locking handle Sto the outer part of the slot R to prevent the return of the lug P, thedisc B will thus be locked with all the grousers in their inoperativeposit-ions. As shown best in F igures 8 and 5, locking handle S isfreely mounted upon the reduced stem 25" of a locking stop T which liesin the space intermediate the inner face of wheel A and the outer faceof disc B and normally out of the path of lug P. Stop T is also providedwith a threaded portion t which extends through slot R and to which stem26' is secured. Between the stop portion T and the threaded portion tthere is a collar i which is wider than slot R. Threaded onto portion tthere is a nut U which bears against awasher V, also wider than slot R.The hub s"oflever S supported on stem .t is normally disconnected fromnut U, but is providedwith radial teeth or projections 5 adapted toengage corresponding teeth or grooves .14 formed onnut U. If lever S ismovedto the. left, as viewedin Figure 5, so that teeth 8 engage teeth a,it is evident that nut U maybe rotated so as toeither re lease or clampstop T in any desired osition relativeto slot path of lug PL g f Eachvof the levers -D' may bev provided with more than one tooth; an exampleof a segment with two teeth is illustrated in Figure 6.v The teeth ;maybe skewed or stag gored, as shown in Fig. 9, in order toincrease thewidth of the track in which they touchthe ground, and in order that whenR, either in or out'o the in the collapsed position each se gment canoverlap the adjacent segment,-

Referring now to the modus operandi of the present invention, the normaldirection of rotation of; wheel A is clockwise, as viewed in Figure 1,and the normal, out- .wardly protruding, operative position of grousersC is substantiallyas shown in the same view. It will thus be seen thatas the wheel rotates, the forces acting upon the grousers tending toforce them outward are the pressure of sprinjgs F, and, centrifugalforce, while positively limiting theoutward movementarestops a; v

Nowv assumingfthat line mew represents the surface of the ground uponwhich wheel A is rolling, when. the tip 0 of a grouser C' initiallystrikesfthe ground, a component of the axle weight of the wheel andvehicie actsupon tip 0 and is opposed by the re-, action of the ground.This latter oppos1ngforce is dependent upon the. hardness of the ground,and normally acts to overcome the outward pressure of spring F andcentrifugal force tending to cause penetration, and tot'orce thegrouserinward However, by the construction :hereindisclosed, it ispossible to utilize this component of weight ,to, momentarily augmentand supplement, instead of to oppose, the spring pressure andcentrifugal force, and thus hard ground. This important, beneficialresult the ground line, represented by line w a'a,

intersects said ground line behind,;or' to the contact between tip 0 andthe ground lines Under these circumstances, the resistance of the groundto penetration,-which may-be represented in a force diagram (Figure 7)by a vertical, upward'directing force vector 09", creates a turning,moment about pivot a. tending to movetip 0 -counterclockwise, or furtheroutward from wheel A." This movement is positively prevented by stop a?with the consequence that vector '07 is opposed by an equal and oppositevector 01 ,"'leaving anunbalanced force 010, due

to the component of theiweight ofthe wheel and vehicle, plus springpressure and centrifugal force, acting on tip .0 to cause initialpenetration by'the grouser. V

v The' additional force thus obtained tendingfto cause initial.jpenetration of the grousers, diminishes rapidly, however, .as forward.motion of the vehicle continues and when line passes forwardof the leftasflviewed in Figure 1', ofithepo int of;

point of contact'between 'tip c and the I ground, the effectof theground resistance is reversed and'thenceforth tends to causeretractionof. the grouser. However, once initial penetration has g beeneffected, another. force, that of the torque upon the wheel,: bQCOlIlQSactive in t'tendingtoucause deeper penetration of 3' the grouser. The

forcesythen acting, as shown, in Figure 8,

are or, resistance of the ground which is now nolOngeropposed by 011 0w, and'ot, a portion of the torque upon the wheel,.the' verticalresultant of which forces, 08, causes further penetration bythe grouser.

termed a condition of automatic torque penetration by the grousers,since with the.

weight of the wheel and vehicleconstant,

too

There is thus established what. may .be

grouser penetrationisautomatically adjusted or regulated to thecondition .of 'the soil,

depending as to its degreeof effectiveness I (distance oryjdepth ofpenetration) upon. the power of the engine of thejvehicle: at a given.-road speed, i.-e.,' torque upon. the wheel. Fromthe above it will beseen that the: effect .of the axle weight. of the vehicle.

in. aiding initial penetration may be varied by. altering the relativepositions. of pivot 09 and tip 0. of the fgrouser,the greaterthedistance between pivot a and a line drawn from .the center of wheel A.to tip a of the i grouser, the less the effect. of the weightuin aiding.penetratlo n What I claim. and desire. to secure by Let tjers Patentofthe United States is :Q-

' L' In a'road vehicle wheel, a rim having anfextension alongside thetread, a control disc angularly movable co-axially with the wheel, aplurality of toothed 'gi'ouserseach comprising arigid lever pivotallyconnected with said extension and operatively connect ed with thecontrol disc,-p'rojections onlthe control disc, the wheel beingprovidedwith=- and springs secured to the wheel and adapted to impelsaid projections in said slots to rock the control disc, whereby thegrousers are rocked relatively to the wheel rim extension to protrudetheir teeth beyond the tread of the wheel.

2. In a road vehicle wheel, a rim having an extension alongside thetread, a control disc angularly movable co-axially with the wheel, aplurality of toothed grousers each pivoted to said extension, each ofsaid grousers having a slottedcranked arm, pins on the control discmovable in the slots of said cranked arms, projections on the controldisc, the wheel having slots receiving said projections, and springssecured to the wheel and adapt ed to impel said projections in saidslots in the wheel to rock the control disc, whereby the grousers arerocked relatively to the wheel rim extension to protrude their teethbeyond the tread of the wheel.

3. In a road vehicle wheel, a rim having an extension alongside thetread, a control disc angularly movable co-axially with the wheel, aplurality of toothed grousers each comprising a plurality of teeth instaggered arrangement and an integral rigid lever pivotally connectedwith said extension and operatively connected with the control disc,projections on said control disc, the wheel having slots receiving saidprojections, and springs secured to the wheel and adapted to impel saidprojections in said slots to rock the control disc, whereby the grousersare rocked relatively to the wheel rim extension to protrude their teethbeyond the tread of the wheel. V

4. In a road vehicle wheel, a plurality of toothed grousers pivotallymounted on said wheel, a control disc carried by but angularly movablerelative to said wheel and having operative connections with saidgrousers, a spring acting to impel the disc to rock in one direction andcause the teeth of the grousers to protrude beyond the periphery of thewheel, a lever movable relative to but having operative engagement withthe control disc and adapted to rock said'control disc in the reversedirection to retract said teeth independently of the motion of thewheel, and means for actuating said lever.

5. In a road vehicle wheel, a plurality of toothed grousers pivotallymounted on said wheel. a control disc carried by but angular- .lymovable relative to said wheel and having operative connections withsaid grousers, a spring acting to impel the disc to rock in onedirection to cause the teeth of the grousers to protrude beyond theperiphery of the wheel, the control disc having a slot formed therein, alever movable. in said slot in the control disc and adapted to rock thedisc in the reverse direction to retract the grouser teeth, and means toactuate said lever comprising an axially movable socket adapted to bereciprocated by a lever under the control of the driver while thevehicle is travelling.

6. In a vehicle wheel, a rim, a plurality of grousers having toothedtips adapted to protrude beyond the rim and to penetrate the ground,pivots for said grousers secured to the rim, resilient means fornormally urging said grousers to an outwardly protruding,operativeposition, and a plurality of stops for positively limiting theextent of said outward movement, said pivots and stops being so locatedwith respect to said tips that at the instant of initial contact betweena grouser tip and the ground the axle Weight of the Wheel and vehicle iseliective' to augment the pressure of said resilient means for causingpenetration of'the ground by the grouser tip.

7. A vehicle wheel including a rim, a plurality of toothed grouserspivotally mounted on said rim, and adapted to pene mate the ground,resilient means for normally urging said grousers to protrude outwardlybeyond said rim into operative position, and means for rendering theaxle weight of the Wheel and vehicle effective to augment the pressureof said resilient means at the instant of initial contact between agrouser and the ground for causing penetration of the ground by thegrouser.

8. In a vehicle wheel, a rim, a plurality of grousers having toothedtips adapted to protrude beyond the rim and to penetrate the ground,pivots for said grousers secured to the rim, levers connecting thepivots and toothed tips of said grousers, resilient means for normallyurging said grousers to an outwardly protruding, operative position, anda plurality of stops for positively limiting the extent of said outwardmovement, said pivots and stops being so located with respect to saidtips and said levers being s0 7 Constructed and arranged that the amountoi. penetration of the ground by the grousers is automatically adjusteddependent upon the resistance of the ground and the torque upon thewheel.

NICHOLAS STRAUSSLER.

